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      1 /*
      2 * Copyright 2015 The Android Open Source Project
      3 *
      4 * Licensed under the Apache License, Version 2.0 (the "License");
      5 * you may not use this file except in compliance with the License.
      6 * You may obtain a copy of the License at
      7 *
      8 *     http://www.apache.org/licenses/LICENSE-2.0
      9 *
     10 * Unless required by applicable law or agreed to in writing, software
     11 * distributed under the License is distributed on an "AS IS" BASIS,
     12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13 * See the License for the specific language governing permissions and
     14 * limitations under the License.
     15 */
     16 
     17 package com.example.android.system.runtimepermissions.camera;
     18 
     19 import android.hardware.Camera;
     20 import android.os.Bundle;
     21 import android.support.v4.app.Fragment;
     22 import android.util.Log;
     23 import android.view.LayoutInflater;
     24 import android.view.View;
     25 import android.view.ViewGroup;
     26 import android.widget.FrameLayout;
     27 import android.widget.Toast;
     28 
     29 import com.example.android.system.runtimepermissions.R;
     30 
     31 /**
     32  * Displays a {@link CameraPreview} of the first {@link Camera}.
     33  * An error message is displayed if the Camera is not available.
     34  * <p>
     35  * This Fragment is only used to illustrate that access to the Camera API has been granted (or
     36  * denied) as part of the runtime permissions model. It is not relevant for the use of the
     37  * permissions API.
     38  * <p>
     39  * Implementation is based directly on the documentation at
     40  * http://developer.android.com/guide/topics/media/camera.html
     41  */
     42 public class CameraPreviewFragment extends Fragment {
     43 
     44     private static final String TAG = "CameraPreview";
     45 
     46     /**
     47      * Id of the camera to access. 0 is the first camera.
     48      */
     49     private static final int CAMERA_ID = 0;
     50 
     51     private CameraPreview mPreview;
     52     private Camera mCamera;
     53 
     54     public static CameraPreviewFragment newInstance() {
     55         return new CameraPreviewFragment();
     56     }
     57 
     58     /**
     59      * A safe way to get an instance of the Camera object.
     60      */
     61     public static Camera getCameraInstance(int cameraId) {
     62         Camera c = null;
     63         try {
     64             c = Camera.open(cameraId); // attempt to get a Camera instance
     65         } catch (Exception e) {
     66             // Camera is not available (in use or does not exist)
     67             Log.d(TAG, "Camera " + cameraId + " is not available: " + e.getMessage());
     68         }
     69         return c; // returns null if camera is unavailable
     70     }
     71 
     72     @Override
     73     public View onCreateView(LayoutInflater inflater, ViewGroup container,
     74             Bundle savedInstanceState) {
     75 
     76         // Open an instance of the first camera and retrieve its info.
     77         mCamera = getCameraInstance(CAMERA_ID);
     78         Camera.CameraInfo cameraInfo = null;
     79 
     80         if (mCamera != null) {
     81             // Get camera info only if the camera is available
     82             cameraInfo = new Camera.CameraInfo();
     83             Camera.getCameraInfo(CAMERA_ID, cameraInfo);
     84         }
     85 
     86         if (mCamera == null || cameraInfo == null) {
     87             // Camera is not available, display error message
     88             Toast.makeText(getActivity(), "Camera is not available.", Toast.LENGTH_SHORT).show();
     89             return inflater.inflate(R.layout.fragment_camera_unavailable, null);
     90         }
     91 
     92         View root = inflater.inflate(R.layout.fragment_camera, null);
     93 
     94         // Get the rotation of the screen to adjust the preview image accordingly.
     95         final int displayRotation = getActivity().getWindowManager().getDefaultDisplay()
     96                 .getRotation();
     97 
     98         // Create the Preview view and set it as the content of this Activity.
     99         mPreview = new CameraPreview(getActivity(), mCamera, cameraInfo, displayRotation);
    100         FrameLayout preview = (FrameLayout) root.findViewById(R.id.camera_preview);
    101         preview.addView(mPreview);
    102 
    103         return root;
    104     }
    105 
    106     @Override
    107     public void onPause() {
    108         super.onPause();
    109         // Stop camera access
    110         releaseCamera();
    111     }
    112 
    113     private void releaseCamera() {
    114         if (mCamera != null) {
    115             mCamera.release();        // release the camera for other applications
    116             mCamera = null;
    117         }
    118     }
    119 }
    120